Thermostatically regulated circulating system



F 1934- w. A. GEISE THERMOSTATICALLY REGULATED CIRCULATING SYSTEM FiledJune 27, 1932 wife? 4 923:36

Patented Feb. 20, 1934 PATENT OFFICE THERMO STATICALLY REGULATEDGIRCULATING SYSTEM Walter A. Geise, Flint, Mich, assignor to GeneralMotors Corporation, Detroit, Mich., a corporation of DelawareApplication June 27, 1932. Serial No. 619,400

3 Claims. (Cl. 123-178) This invention relates to liquid cooled internalcombustion engines and, particularly, to the cooling liquid circulatingsystems of such engines and resides in a cooling liquid circulatingsystem which includes the cooling liquid jacket of the engine, a liquidcooling radiator, a passage I through which. cooling liquid may beby-passed around the radiator and independently thermostaticallyoperated valves for regulating the flow of cooling liquid through theradiator and the by-passage.

For a better understanding of the nature and the objects of the presentinvention, reference is made to the following specification in whichthere is described the preferred embodiment of my invention which isillustrated in the accompanying drawing.

In the accompanying drawing:

Figure 1 is a fragmentary view of an internal combustion engine equippedwith a cooling liquid circulating system in accordance with myinvention.

Figure 2 is an enlarged fragmentary rear elevation of the upper tank ofthe radiator shown in Figure 1.

Figures 3 and 4 are fragmentary sections taken, respectively, on thelines 3-3 and 4-4 of Figure 2.

In the drawing, the reference character indicates an internal combustionengine of the liquid-cooled type and the reference character 11 aradiator whose upper and lower tanks 12 and 13 are connected by a core14 in which there are provided liquid cooling passages between which airis adapted to be drawn by the engineoperated fan 15. In advance of theradiator, there is located a conduit 16 whose lower end communicateswith the lower tank of the radiator and whose upper end communicateswith the forward end of a tube 1'7 which extends through the front andrear walls of the upper tank of the radiator. 1

The lower tank of the radiator is connected to the inlet of the coolingliquid jacket of the engine 10 by a conduit 18 and an engine operatedcooling liquid circulating pump 19. To the outlet 20 of the coolingliquid jacket of the engine, there is connected a conduit 21 to whichthere is connected an elbow 22 in which there is provided a passage 23which communicates with the tube V 1'7 and a passage 24 whichcommunicates with the passage 23 and an opening 31 in the rear wall ofthe upper tank of the radiator.

In the passage 23-1'7, there is located a thermostatically operatedvalve unit 25 which consists of a tubular housing 26 in which there ispivotally mounted a valve 2'7 of the butterfly type located. within thetube 1'7 and a thermosensitive element 28 of the volatile-liquid-filledexpansible and contractible bellows type located 60 in the passage 23and so connected to the valve 27 by a lever 29 that when the temperatureof the thermo-sensitive element increases it tends to close the passage23-1'7, and when the temperature thereof decreases it tends to, open thepassage 231'7.

In'the passage 2431, there is located a thermostat-ically operated valveunit 30 which includes a valve seat 32 located in the opening 31 and aperforated cage 33 which extends into the 7 passage 24 and to whose enddistant from the opening 31 there is fixed one end of a thermosensitiveelement 34 of the volatile-liquid-filled expansible and contractible'bellows type whose opposite end is connected to a valve 35 of the poppettype by a stem 36 so that when the temerature of the thermo-sensitiveelement increases it tends to open the passage 24-31 and when thetemperature thereof decreases it tends to close the passage 24-31.

It will be apparent from the foregoing description that cooling liquidwithdrawn from the lower tank 13 of the radiator 11 by the pump 19 may,after passing through the cooling liquid jacket of the engine 10, returnto the lower tank of the ra- 86 diator either through the core 14 of theradiator or through the conduit 16. In'the former event, the temperatureof the cooling liquid entering the lower tank will be considerably lowerthan that of the cooling liquid leaving theco'oling liquid 90 jacket ofthe engine but, in the latter event, the temperature of the coolingliquid entering the lower tank will not differ appreciably from that ofthe cooling liquid leaving the cooling liquid jacket of the engine.Whether the cooling liquid which leaves the cooling liquid jacket of theengine will return to the lower tank of the radiator by way of the core14 or by way of the conduit 16 or in part by way of the core and in partby way of the conduit and, in the latter event, what proportion willreturn by way of the core and what proportion by way of the conduit,and, consequently, the difference between the temperature of' thecooling liquid leaving the cooling liquid jacket of the engine and thatof the cooling liquid entering the lower tank of the radiator willdepend upon the positions of the valves 27 and 35 and, consequently,upon the temperature of the cooling liquid leaving the cooling liquidjacket of the engine. Since the valves 2'7 and 35 are oper- 11o ated byindependent thermo-sensitive elements, the position of one of the valvesis in nowise dependent upon the position of the other, and,consequently, the flow of cooling liquid through the core will beregulated independently of that through the conduit 16. Obviously,regulation of the flow of cooling liquid through the core independentlyof that through the conduit makesit possible to control the flow and,consequently, the

temperature of the cooling liquid in the cooling liquid circulatingsystem of the engine much more effectively than is possible through theuse of a single thermostatically operated valve or by the use of twovalves operated by a single thermosensitive element. Although it isobvious that if properly calibrated thermo-sensitive elements are usedany desired relation between the opening and closing movements of thevalves 27 and 35 may be obtained, I consider it preferable, in order toinsure that the engine will reach its optimum operating temperature asquickly as possible and will be maintained at this temperature and tomaintain the pressure of the cooling liquid in the cooling liquidcirculating systems of the engine at a minimum at all times, so tocalibrate the thermo-sensitive elements that when the engine is cold thevalve 27 will be fully open and the valve 35 fully closed, that thevalve 27 will not begin to close until the temperature of the coolingliquid leaving the cooling liquid jacket of the engine is sufiicientnearly to fully open the valve 35 and that the valve 27 will not reachfully closed position and the valve 35 fully open when the engine isoperating at its optimum operating tempera-- ture.

It is obvious that the embodiment of themvention disclosed herein may bemodified in various ways, as by using valves and/or thermosensitiveelements of types different from those shown and described and/or bychanging the 10- cations of the thermostatically operated valve units.

I claim:

- 1. In an internal combustion engine in which there is provided acooling liquid circuit which includes a cooling liquid jacket, a liquidcooling radiator and a radiator by-passage: a thermostatically operatedvalve which tends to open as the temperature of the cooling liquid isincreased to regulate the flow of cooling liquid through the radiator,and an independently thermostatically operated valve which tends toclose as the temperature of the cooling liquid is increased to regulatethe flow of cooling liquid through the bypassage.

2. The invention claimed in claim 1 in which the second-mentioned valvebegins to close only after the first-mentioned valve nearly reachesfully open position. I

3. In an internal combustion engine, a cooling liquid jacket, a liquidcooling radiator which includes a core and tanks communicatingtherewith, a conduit for conducting heated cooling liquid from thejacket to one of the tanks, a conduit for conducting cooled coolingliquid from the other of the tanksto the jacket, a conduit communicatingat one end with the first-mentioned conduit, extending through thefirst-mentioned tank and communicating at the other end with thesecond-mentioned tank, a thermostatically operated valve which tends toopen as the temperature of the cooling liquid is increased associatedwith the first-mentioned conduit and the first-mentioned tank toregulate the flow of cooling liquid through the radiator, and anindependently thermostatically operated valve which tends to close asthe temperature of the cooling liquid is increased associated with thefirst-mentioned and third-mentioned conduits to regulate the flow ofcooling liquid through the third-mentioned conduit.

WALTER A. GEISE.

